Respiratory Diseases

Bronchodilators are used in the treatment of asthma, chronic bronchitis, and emphysema. A bronchodilator is a medicine used to relax the muscles of the bronchial tubes. It is usually administered as a mist through an inhaler. Some are given orally as a tablet. Administered with an inhaler, they go straight to the lungs for fast action. Since they do not enter the bloodstream, they have few side effects.

Anticholinergic bronchodilators are also taken by inhalation. They take more time to work than the sympathomimetic medicines, but they remain effective for a longer period of time. Their job is more prevention than immediate relief. They work by countering signals from the parasympathetic nervous system to constrict the bronchioles. These signals send their messages to the cholinergic receptors on the muscle wall of the bronchioles. The anticholinergic medicine blocks the receptor. Atropine is an example of an anticholinergic bronchodilator.

Xanthines date back to the ancient world. They have been used as medicines for a number of conditions. Caffeine is a type of xanthine. Theophylline is the active ingredient of the xanthines. They relax smooth muscle and stimulate the heart. They are particularly effective in relaxing the muscle walls of the bronchioles. Taken orally, they act directly on the muscle tissue. It is not certain how the xanthines work, but they seem to prevent mast cells from releasing histamines while inhibiting other enzymatic actions.